Abstract:

An organic light emitting diode is disclosed, and includes a
light-efficiency-improvement layer containing a compound represented by
Formula 1:
##STR00001##

Claims:

1. An organic light emitting diode comprising:a substrate;a first
electrode defining first and second surfaces opposite one another, the
second surface facing the substrate;an organic layer facing the first
surface of the first electrode;a second electrode defining first and
second surfaces opposite one another, the first surface facing the
organic layer; anda light-efficiency-improvement layer in contact with at
least one of the second surface of the first electrode or the second
surface of the second electrode and comprising a compound represented by
Formula 1: ##STR00045## whereAr is a substituted or unsubstituted
C5-C30 aromatic ring system or a substituted or unsubstituted
C2-C30 hetero aromatic ring system;each L1 is
independently selected from the group consisting of substituted or
unsubstituted C1-C30 alkylene groups, substituted or
unsubstituted C5-C30 arylene groups, and substituted or
unsubstituted C2-C30 hetero arylene groups;X1 is N,
CY1, or a carbon atom bonded to L1 or Ar;X2 is N,
CY2, or a carbon atom bonded to L1 or Ar;X3 is N,
CY3, or a carbon atom bonded to L1 or Ar;X4 is N;X5
is a carbon atom;X6 is N or CY6;wherein one of X1,
X2, and X3 is a carbon atom bonded to L1 or Ar;each of
R1 through R3 and Y1 through Y6 is independently
selected from the group consisting of a hydrogen atom, halogen atoms, a
hydroxyl group, a cyano group, substituted or unsubstituted
C1-C30 alkyl groups, substituted or unsubstituted
C1-C30 alkoxy groups, substituted or unsubstituted
C1-C30 acyl groups, substituted or unsubstituted
C2-C30 alkenyl groups, substituted or unsubstituted
C2-C30 alkynyl groups, substituted or unsubstituted
C5-C30 aryl groups, and substituted or unsubstituted
C2-C30 hetero aryl groups, wherein two or more adjacent
elements selected from R1 through R3 and Y1 through
Y6 may be bonded to each other to form a saturated or unsaturated
ring;a is an integer from 0 to 10;m is an integer from 1 to 5; andn is an
integer from 1 to 10.

3. The organic light emitting diode of claim 1, wherein, when Ar is a
substituted C5-C30 aromatic ring system or a substituted
C2-C30 hetero aromatic ring system, a substituent is selected
from the group consisting of substituted or unsubstituted
C6-C14 aryl groups and substituted or unsubstituted
C2-C14 hetero aryl groups.

5. The organic light emitting diode of claim 1, wherein each L1 is
independently selected from the group consisting of substituted or
unsubstituted C6-C14 arylene groups and substituted or
unsubstituted C2-C14 hetero arylene groups.

7. The organic light emitting diode of claim 1, wherein -(L1)a-
is represented by any one formula selected from Formulae 2a through 2g:
##STR00046##

8. The organic light emitting diode of claim 1, wherein at least one of
X1, X4 and X6 is N.

9. The organic light emitting diode of claim 1, wherein each of X1
and X4 is N.

10. The organic light emitting diode of claim 1, wherein each of X1,
X4 and X6 is N.

11. The organic light emitting diode of claim 1, wherein each of R1
through R3 and Y1 through Y6 is independently selected
from the group consisting of a hydrogen atom, substituted or
unsubstituted C1-C10 alkyl groups, substituted or unsubstituted
C2-C10 alkenyl groups, substituted or unsubstituted
C6-C14 aryl groups, and C2-C14 hetero aryl groups.

14. The organic light emitting diode of claim 1, wherein the compound
represented by Formula 1 is a compound represented by any one formula
selected from Formulae 1A through 1X: ##STR00047## ##STR00048##
##STR00049## ##STR00050## ##STR00051## ##STR00052## whereeach of
Q1 through Q11 is independently selected from the group
consisting of a hydrogen atom, substituted or unsubstituted
C6-C14 aryl groups, and substituted or unsubstituted
C2-C14 hetero aryl groups;each of L1 is independently
selected from the group consisting of substituted or unsubstituted
C6-C14 arylene groups and substituted or unsubstituted
C2-C14 hetero arylene groups;each of R1, R2, R3,
Y2 and Y3 is independently selected from the group consisting
of a hydrogen atom, substituted or unsubstituted C1-C10 alkyl
groups, substituted or unsubstituted C2-C10 alkenyl groups,
substituted or unsubstituted C6-C14 aryl groups, and
C2-C14 hetero aryl groups, wherein two or more adjacent
elements selected from R1 through R3 and Y1 through
Y6 may be bonded to each other to form a C6-C12 aromatic
ring; anda is 1 or 2.

15. The organic light emitting diode of claim 14, wherein Q1 through
Q11 are each independently a hydrogen atom, a phenyl group, a
halophenyl group, a C1-C10 alkylphenyl group, a
C1-C10 alkoxyphenyl group, a naphthyl group, a halonaphthyl
group, a C1-C10 alkylnaphthyl group, a C1-C10
alkoxynaphthyl group, a pyridinyl group, a halopyridinyl group, a
C1-C10 alkylpyridinyl group, a C1-C10 alkoxypyridinyl
group, a quinolinyl group, a haloquinolinyl group, a C1-C10
alkylquinolinyl group, a C1-C10 alkoxyquinolinyl group, an
isoquinolinyl group, a haloisoquinolinyl group, a C1-C10
alkylisoquinolinyl group, or a C1-C10 alkoxyisoquinolinyl
group.

16. The organic light emitting diode of claim 1, wherein the second
electrode is a transmission-type electrode and the
light-efficiency-improvement layer is in contact with the second surface
of the second electrode.

17. The organic light emitting diode of claim 1, wherein the first
electrode is a transmission-type electrode and the
light-efficiency-improvement layer is in contact with the second surface
of the first electrode.

18. The organic light emitting diode of claim 1, wherein the first
electrode and the second electrode are transmission-type electrodes and a
light-efficiency-improvement layer is in contact with the second surface
of the first electrode and a light-efficiency-improvement layer is in
contact with the second surface of the second electrode.

19. The organic light emitting diode of claim 1, wherein the organic layer
is individually formed corresponding to R, G and B pixels and the
light-efficiency-improvement layer is a common layer with respect to the
R, G and B pixels.

20. The organic light emitting diode of claim 1, wherein the organic layer
is individually formed corresponding to R, G and B pixels and the
light-efficiency-improvement layer comprises at least one layer selected
from the group consisting of a light-efficiency-improvement layer-R
formed corresponding to the R pixel, a light-efficiency-improvement
layer-G formed corresponding to the G pixel, and a
light-efficiency-improvement layer-B formed corresponding to the B pixel.

22. The organic light emitting diode of claim 21, wherein the
light-efficiency-improvement layer-R, the light-efficiency-improvement
layer-G and the light-efficiency-improvement layer-B have the same or
different thicknesses.

Description:

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001]This application claims priority to and the benefit of Korean Patent
Application No. 10-2008-0080567, filed in the Korean Intellectual
Property Office on Aug. 18, 2008, the entire content of which is
incorporated herein by reference.

[0004]In general, an organic light emitting diode includes a substrate, an
anode disposed on the substrate, a hole transport layer, an emission
layer, an electron transport layer and a cathode, which are sequentially
disposed on the anode in this order. Herein, the hole transport layer,
the emission layer and the electron transport layer are organic thin
films.

[0005]An operational principle of the organic light emitting diode will
now be described in detail.

[0006]When voltage is applied between the anode and the cathode, holes
injected from the anode move to the emission layer through the hole
transport layer and electrons injected from the cathode move to the
emission layer through the electron transport layer. The holes and
electrons which are carriers are recombined in the emission layer,
thereby generating exitons. The exitons are transited from an excited
state to a ground state, thereby generating light.

[0007]Light efficiency of organic light emitting diodes can be categorized
into internal luminescent efficiency and external luminescent efficiency.
Internal luminescent efficiency relates to how efficiently exitons are
generated in an organic layer interposed between a first electrode and a
second electrode, that is, between the anode and the cathode and light is
converted, wherein the organic layer may be a hole transport layer, an
emission layer, or an electron transport layer. External luminescent
efficiency (hereinafter also referred to as light coupling efficiency)
relates to how efficiently light generated in the organic layer is
emitted outside the organic light emitting diode. Accordingly, even if
the organic layer has high light conversion efficiency, that is, the
internal luminescent efficiency is high, when the light coupling
efficiency is low, the whole light efficiency of the organic light
emitting diode may be decreased.

[0009]According to an aspect of the present invention, an organic light
emitting diode is provided that includes: a substrate; a first electrode
disposed on the substrate; an organic layer disposed on the first
electrode; a second electrode disposed on the organic layer; and a
light-efficiency-improvement layer, wherein the first electrode has a
first surface contacting with the organic layer and a second surface
being opposite to the organic layer, the second electrode has a first
surface contacting with the organic layer and a second surface being
opposite to the organic layer, and the light-efficiency-improvement layer
is formed on at least one of the second surface of the first electrode
and the second surface of the second electrode and comprises a compound
represented by Formula 1:

##STR00002##

where Ar is a substituted or unsubstituted C5-C30 aromatic ring
system or a substituted or unsubstituted C2-C30 hetero aromatic
ring system; L1 is a substituted or unsubstituted C1-C30
alkylene group, a substituted or unsubstituted C5-C30 arylene
group, or a substituted or unsubstituted C2-C30 hetero arylene
group; X1 is N, CY1, or a binding site with L1 or Ar,
X2 is N, CY2, or a binding site with L1 or Ar, X3 is
N, CY3, or a binding site with L1 or Ar, X4 is N,
CY4, or a binding site with L1 or Ar, X5 is N, CY5,
or a binding site with L1 or Ar, and X6 is N, CY6, or a
binding site with L1 or Ar, wherein any one of X1 through
X6 is a binding site with L1 or Ar; each of R1 through
R3 and Y1 through Y6 is independently selected from a
hydrogen atom, a halogen atom, a hydroxyl group, a cyano group,
substituted or unsubstituted C1-C30 alkyl groups, substituted
or unsubstituted C1-C30 alkoxy groups, substituted or
unsubstituted C1-C30 acyl groups, substituted or unsubstituted
C2-C30 alkenyl groups, substituted or unsubstituted
C2-C30 alkynyl groups, substituted or unsubstituted
C5-C30 aryl groups, or substituted or unsubstituted
C2-C30 hetero aryl groups, wherein two or more adjacent
elements selected from R1 through R3 and Y1 through
Y6 are bonded to each other to form a saturated or unsaturated ring;
a is an integer of 0 through 10; m is an integer of 1 through 5; and n is
an integer of 1 through 10.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]The above and other features and advantages of the present invention
will become more apparent by describing in detail exemplary embodiments
thereof with reference to the attached drawings in which:

[0011]FIG. 1 is a schematic view of an organic light emitting diode
according to an embodiment of the present invention;

[0012]FIG. 2 is a schematic view of an organic light emitting diode
according to another embodiment of the present invention; and

[0013]FIG. 3 is a schematic view of an organic light emitting diode
according to another embodiment of the present invention.

DETAILED DESCRIPTION

[0014]The present invention will now be described more fully with
reference to the accompanying drawings, in which exemplary embodiments of
the invention are shown.

[0015]FIG. 1 is a schematic view of an organic light emitting diode (OLED)
10 according to an embodiment of the present invention.

[0016]Referring to FIG. 1, the OLED 10 according to the present embodiment
includes a substrate 11, a first electrode 13, an organic layer 15, a
second electrode 17, and a light-efficiency-improvement layer 18, which
are sequentially formed in this order. The second electrode 17 may be a
transmission-type electrode, and light generated in the organic layer 15
is emitted outside the organic light emitting diode 10 through the second
electrode 17 and the light-efficiency-improvement layer 18.

[0017]The substrate 11 may be any substrate that is used in a conventional
organic light emitting diode. In this regard, the substrate 11 may be a
glass or transparent plastic substrate that has mechanical strength,
thermal stability, a flat surface, convenience for handling, is
transparent, and is waterproof.

[0018]The first electrode 13 may be formed by depositing or sputtering a
first electrode forming material on the substrate 11. The first electrode
13 has a first surface contacting the organic layer 15 and a second
surface opposite the organic layer 15. When the first electrode 13 is an
anode, the first electrode forming material may be selected from
materials having a high work function so that holes are easily injected.
The first electrode 13 may be a reflection-type electrode or a
transmission-type electrode. The first electrode forming material may be
a transparent, conductive material, such as indium tin oxide (ITO),
indium zinc oxide (IZO), thin oxide (SnO2), or zinc oxide (ZnO).
When the first electrode 13 is a reflection-type electrode, the first
electrode forming material may be magnesium (Mg), aluminum (Al),
aluminum-lithium (Al--Li), calcium (Ca, magnesium-indium (Mg--In), or
magnesium-silver (Mg--Ag).

[0019]The organic layer 15 may be disposed on the first electrode 13. In
the current specification, the term "organic layer" refers to a layer
interposed between the first electrode 13 and the second electrode 17,
and the organic layer may include materials other than purely organic
materials. In this regard, the organic layer can also include a metal
complex.

[0020]The organic layer 15 may include at least one layer selected from
the group consisting of a hole injection layer (HIL), a hole transport
layer (HTL), an emission layer (EML), a hole blocking layer (HBL), an
electron transport layer (ETL), and an electron injection layer (EIL).

[0021]An HIL may be formed on the first electrode 13 using any known
method, such as a vacuum-deposition method, a spin-coating method, a
casting method, or a Langmuir-Blodgeft (LB) deposition method.

[0022]If the HIL is formed using the vacuum-deposition method, deposition
conditions may differ according to an HIL forming material, the target
layer structure, and thermal characteristics. In this regard, in general,
the deposition temperature may be 100 to 500° C, the vacuum
deposition pressure may be 10-8 to 10-3 torr, and the
deposition rate may be 0.01 to 100 Å/sec.

[0023]If the HIL is formed using the spin-coating method, coating
conditions may differ according to the HIL forming material, the target
layer structure, and thermal characteristics. In this regard, in general,
the coating rate may be about 2000 rpm to 5000 rpm, and the heat
treatment temperature at which solvent is removed after coating may be
about 80° C. to 200° C.

[0025]In an embodiment, the thickness of the HIL may be about 100 Å to
10000 Å In another embodiment, the thickness may be 100 Å to 1000
Å. If the thickness of the HIL is within this range, appropriate hole
injection characteristics may be obtained without a substantial increase
in the driving voltage.

[0026]Then an HTL may be formed on the HIL using any known method, such as
a vacuum-deposition method, a spin-coating method, a casting method, or
an LB deposition method. When the HTL is formed using the
vacuum-deposition method or the spin-coating method, deposition
conditions and coating conditions may differ according to an HTL forming
material. In this regard, deposition conditions and coating conditions
may be the same or similar to those described with reference to the HIL.

[0027]The HTL forming material may be any known hole transportable
material. Examples of the hole transportable material include: a
carbazole derivative such as N-phenylcarbazole or polyvinylcarbazole; an
amine derivative having an aromatic condensation ring, such as
N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD)
illustrated below or N,N'-di(naphthalene-1-yl)-N,N'-diphenyl benzidine
(α-NPD) illustrated below; and a triphenylamine-based material,
such as 4,4',4''-tris(N-carbazolyl)triphenylamine(4,4',4''-tris(N-carbazo-
lyl)triphenylamine) (TCTA). Specifically, TCTA may have, in addition to a
hole transporting capability, a capability of blocking diffusion of
exitons generated in the EML.

##STR00004##

[0028]In an embodiment, the thickness of the HTL may be about 50 Å to
1000 Å. In another embodiment, the thickness may be 100 Å to 800
Å. If the thickness of the HTL is within this range, appropriate hole
transporting characteristics can be obtained without a substantial
increase in the driving voltage.

[0029]Then an EML may be formed on the HTL using any known method, such as
a vacuum-deposition method, a spin-coating method, a casting method, or
an LB deposition method. When the EML is formed using the
vacuum-deposition method or the spin-coating method, deposition
conditions and coating conditions may differ according to an EML forming
material. In this regard, deposition conditions and coating conditions
may be the same or similar to those described with reference to the HIL.

[0030]The EML may include a compound or a combination of a host and a
dopant.

[0032]Meanwhile, examples of a known red dopant include PtOEP,
Ir(piq)3, Btp2Ir(acac), which are illustrated below, and DCJTB.
However, the red dopant is not limited to these materials.

##STR00006##

[0033]Examples of a known green dopant include Ir(ppy)3 where
ppy=phenylpyridine, Ir(ppy)2(acac), Ir(mpyp)3 which are
illustrated below, and C545T. However, the green dopant is not
limited to these materials.

[0035]When the dopant and the host are used together, the doping
concentration of the dopant is not limited. In this regard, the content
of the dopant may be 0.01 to 15 parts by weight based on 100 parts by
weight of the host.

[0036]In an embodiment, the thickness of the EML may be about 100 Å to
1000 Å. In another embodiment, the thickness may be 200 Å to 600
Å. If the thickness of the EML is within this range, excellent
luminescent characteristics can be obtained without a substantial
increase in the driving voltage.

[0037]When the EML is formed using a phosphorescent dopant, diffusion of
triplet exitons or holes into the ETL can be prevented by forming an HBL
between the ETL and the EML using any method selected from a
vacuum-deposition method, a spin-coating method, a casting method, and an
LB deposition method. When the HBL is formed using the vacuum-deposition
method or the spin-coating method, deposition conditions and coating
conditions may differ according to an HBL forming material. In this
regard, deposition conditions and coating conditions may be the same or
similar to those described with reference to the HIL. The HBL forming
material may be any known hole blocking material. In this regard,
examples of the hole blocking material include an oxadiazole derivative,
a triazole derivative, and a phenanthroline derivative.

[0038]In an embodiment, the thickness of the HBL may be about 50 Å to
1000 Å. In another embodiment, the thickness may be 100 Å to 300
Å. If the thickness of the HBL is within this range, excellent hole
blocking characteristics can be obtained without a substantial increase
in the driving voltage.

[0039]Then an ETL may be formed using any known method, such as a
vacuum-deposition method, a spin-coating method, or a casting method.
When the ETL is formed using the vacuum-deposition method or the
spin-coating method, deposition conditions and coating conditions may
differ according to an ETL forming material. In this regard, deposition
conditions and coating conditions may be the same or similar to those
described with reference to the HIL.

[0040]The ETL forming material may be any known electron transporting
material that stably transports electrons injected from an electron
injection electrode, that is, a cathode. Examples of the electron
transporting material include quinoline derivatives, such as
tris(8-quinolinolate)aluminum (Alq3), TAZ illustrated below, and
BAlq illustrated below. However, the ETL forming material is not limited
to these materials.

##STR00009##

[0041]In an embodiment, the thickness of the ETL may be about 100 Å to
1000 Å. In another embodiment, the thickness may be 150 Å to 500
Å. If the thickness of the ETL is within this range, appropriate
electron transporting characteristics can be obtained without a
substantial increase in the driving voltage.

[0042]Then an EIL may be formed by depositing an EIL forming material on
the ETL. The EIL forming material may be a material that allows electrons
to be easily injected. The EIL forming material is not limited, and may
be any known EIL forming material, such as LiF, NaCl, CsF, Li2O, or
BaO. Deposition conditions of the EIL may differ according to the EIL
forming material. In general, deposition conditions may be the same or
similar to those described with reference to the HIL.

[0043]The thickness of the EIL may be about 1 Å to 100 Å. In
another embodiment, the thickness may be 5 Å to 90 Å. If the
thickness of the EIL is within this range, appropriate electron injection
characteristics can be obtained without a substantial increase in the
driving voltage.

[0044]The second electrode 17 that is a transmission-type electrode may be
disposed on the organic layer 15. The second electrode 17 has a first
surface contacting with the organic layer 15 and a second surface being
opposite to the organic layer 15. The second electrode 17 may be a
cathode that is an electron injection electrode. A second electrode
forming metal may be a metal having a low work function, an alloy having
a low work function, an electro-conductive compound, or mixtures thereof.
Specifically, examples of the second electrode forming metal include
lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al--Li),
calcium (Ca), magnesium-indium (Mg--In), and magnesium-silver (Mg--Ag).
Meanwhile, if the OLED 10 according to the current embodiment is a front
emission type device, the second electrode 17 may be a transmission-type
electrode formed of ITO or IZO.

[0045]The light-efficiency-improvement layer 18 is disposed on the second
surface of the second electrode 17.

[0048]In certain embodiments, Ar may be, as described above, in addition
to the unsubstituted C5-C30 aromatic ring system or the
unsubstituted C2-C30 hetero aromatic ring system, the
substituted C5-C30 aromatic ring system or the substituted
C2-C30 hetero aromatic ring system. In the substituted
C5-C30 aromatic ring system or the substituted C2-C30
hetero aromatic ring system, a substituent may be substituted or
unsubstituted C6-C14 aryl groups or substituted or
unsubstituted C2-C14 hetero aryl groups.

[0049]In certain embodiments, the substituent may be a phenyl group, a
halophenyl group, a C1-C10 alkylphenyl group, a
C1-C10 alkoxyphenyl group, a naphthyl group, a halonaphthyl
group, a C1-C10 alkylnaphthyl group, a C1-C10
alkoxynaphthyl group, a pyridinyl group, a halopyridinyl group, a
C1-C10 alkylpyridinyl group, a C1-C10 alkoxypyridinyl
group, a quinolinyl group, a haloquinolinyl group, a C1-C10
alkylquinolinyl group, a C1-C10 alkoxyquinolinyl group, an
isoquinolinyl group, a haloisoquinolinyl group, a C1-C1o
alkylisoquinolinyl group, or a C1-C10 alkoxyisoquinolinyl
group, but is not limited thereto.

[0050]In Formula 1, L1 may be a substituted or unsubstituted
C1-C30 alkylene group, a substituted or unsubstituted
C5-C30 arylene group, or a substituted or unsubstituted
C2-C30 hetero arylene group.

[0051]In certain embodiments, L1 may be a substituted or
unsubstituted C6-C14 arylene group or a substituted or
unsubstituted C2-C14 hetero arylene group. In certain
embodiments, L1 may be a phenylene group, a halophenylene group, a
C1-C10 alkylphenylene group, a C1-C10 alkoxyphenylene
group, a naphthylene group, a halonaphthylene group, a C1-C10
alkylnaphthylene group, or a C1-C10 alkoxynaphthylene group,
but is not limited thereto.

[0052]In Formula 1, a denotes a repeat number of L1, and may be an
integer of 0 to 10. In some embodiments, a may be an integer from 0 to 3.
If a is 0, in Formula 1, a heterocyclic ring situated at the right side
of L1 may be directly connected to Ar. If a is 2 or greater, a
plurality of L1 may be identical to or different from each other.

[0053]In Formula 1, -(L1)a- may be represented by any one of
Formulae 2a through 2g, but is not limited thereto.

##STR00011##

In Formulae 2a-2g, * represents a binding site with Ar and *' represents a
binding site with a heterocyclic ring at the right side of L1 in
Formula 1. For example, -(L1)a- may be represented by Formula
2a.

[0054]For example, in Formula 1, X1 is N, CY1, or a carbon atom
bonded to L1 or Ar; X2 is N, CY2, or a carbon atom bonded
to L1 or Ar; X3 is N, CY3, or a carbon atom bonded to
L1 or Ar; X4 is N; X5 is a carbon atom; X6 is N or
CY6;wherein one of X1, X2 and X3 is a carbon atom
bonded to L1 or Ar. Particularly, X1 may be CY1 or N;
X2 may be a carbon atom bonded to L1 or Ar; X3 may be
CY3 or N; X4 may be N; X5 may be a carbon atom; X6
may be N or CY6.

[0055]In certain embodiments, at least one of X1, X4 and X6
may be N. In certain embodiments, each of X1 and X4 may be N.
In certain other embodiments, each of X1, X4 and X6 may be
N.

[0056]In Formula 1, each of R1 through R3, and Y1 through
Y6 in X1 through X6 is independently a hydrogen atom, a
halogen atom, a hydroxyl group, a cyano group, a substituted or
unsubstituted C1-C30 alkyl group, a substituted or
unsubstituted C1-C30 alkoxy group, a substituted or
unsubstituted C1-C30 acyl group, a substituted or unsubstituted
C2-C30 alkenyl group, a substituted or unsubstituted
C2-C30 alkynyl group, a substituted or unsubstituted
C5-C30 aryl group, or a substituted or unsubstituted
C2-C30 hetero aryl group. In this regard, two or more
neighboring elements selected from R1 through R3 and Y1
through Y6 may be selectively bonded to each other to form a
saturated or an unsaturated ring.

[0057]In certain embodiments, each of R1 through R3 and Y1
through Y6 is independently a hydrogen atom, a substituted or
unsubstituted C1-C10 alkyl group, a substituted or
unsubstituted C2-C10 alkenyl group, a substituted or
unsubstituted C6-C14 aryl group, or a C2-C14 hetero
aryl group.

[0058]In certain embodiments, each of R1 through R3 and Y1
through Y6 is independently selected from a hydrogen atom,
C1-C10 alkyl groups, C1-C10 halo alkyl groups,
C2-C10 alkenyl groups, C2-C10 halo alkenyl groups,
phenyl groups, halophenyl groups, C1-C10 alkylphenyl groups,
C1-C10 alkoxyphenyl groups, naphthyl groups, halonaphthyl
groups, C1-C10 alkylnaphthyl groups, or C1-C10
alkoxynaphthyl groups, but is not limited thereto. For example, each of
R1 through R3 and Y1 through Y6 may be independently
selected from a hydrogen atom, a methyl group, and a phenyl group. For
example, Y3, Y6, R1, R2, and R3 may be a
hydrogen atom. For example, R3 may be selected from a hydrogen atom,
a methyl group and a phenyl group. For example, Y6 and R1 may
be bonded to each other to form a saturated or unsaturated ring, such as
a phenyl ring.

[0059]In Formula 1, m denotes the number of the heterocyclic ring situated
at the right side of L1, wherein the heterocyclic ring can be bonded
to L1 or Ar and m is dependent upon the structure of Ar or L1.
For example, m may be an integer from 1 to 5. For example, m could be 1.

[0060]In Formula 1, n is an integer from 1 to 10, and is dependent upon
the structure of Ar. For example, n could be 1 or 2.

[0061]According to an embodiment of the present invention, the compound
represented by Formula 1 may be any one compound selected from compounds
represented by Formulae 1A through 1X, but is not limited thereto:

[0062]In Formulae 1A through 1X, each of Q1 through Q11 may be
independently a hydrogen atom, a substituted or unsubstituted
C6-C14 aryl group, or a substituted or unsubstituted
C2-C14 hetero aryl group.

[0063]In certain embodiments, each of Q1 through Q11 is
independently selected from a hydrogen atom, phenyl group, a halophenyl
group, a C1-C10 alkylphenyl group, a C1-C10
alkoxyphenyl group, a naphthyl group, a halonaphthyl group, a
C1-C10 alkylnaphthyl group, a C1-C10 alkoxynaphthyl
group, a pyridinyl group, a halopyridinyl group, a C1-C10
alkylpyridinyl group, a C1-C10 alkoxypyridinyl group, a
quinolinyl group, a haloquinolinyl group, a C1-C10
alkylquinolinyl group, a C1-C10 alkoxyquinolinyl group, an
isoquinolinyl group, a haloisoquinolinyl group, a C1-C10
alkylisoquinolinyl group, or a C1-C10 alkoxyisoquinolinyl
group, but is not limited thereto.

[0064]In certain embodiments, in Formulae 1A-1D, and 1M-1P, each of
Q2 and Q7 is a substituted or unsubstituted C6-C14
aryl group or a substituted or unsubstituted C2-C14 hetero aryl
group. That is, in Formulae 1A-1D and 1M-1P, the 9 and 10 positions of an
anthracene ring that correspond to Q2 and Q7 positions may not
be bonded to the heterocyclic ring situated at the right side of L1.
For example, in Formulae 1A-1D and 1M-1P, each of Q2 and Q7 is
independently selected from a phenyl group and a naphthyl group and each
of Q1, Q3-Q6 and Q8-Q9 is a hydrogen atom. This
is because the 9 and 10 positions of the anthracene ring are structurally
weak points. When the 9 and 10 positions of the anthracene ring are
substituted with specific functional groups, the specific functional
groups may be easily separated from the anthracene ring due to heat,
oxygen, and humidity. For example, when the heterocyclic ring situated at
the right side of L1 is connected to the 9 and 10 positions of the
anthracene ring, the heterocyclic ring situated at the right side of
L1 may be easily separated from the anthracene ring due to heat
generated in a process for forming an organic layer of an organic light
emitting diode, for example, a deposition process, or heat generated when
the organic light emitting diode is driven, and thus, characteristics of
the organic light emitting diode may be degraded.

[0065]In Formula 1A through 1X, L1 may be a substituted or
unsubstituted C6-C14 arylene group, or a substituted or
unsubstituted C2-C14 hetero arylene group.

[0066]In certain embodiments, L1 may be a phenylene group, a
halophenylene group, a C1-C10 alkylphenylene group, a
C1-C10 alkoxyphenylene group, a naphthylene group, a
halonaphthylene group, a C1-C10 alkylnaphthylene group, or a
C1-C10 alkoxynaphthylene group, but is not limited thereto.

[0067]In Formulae 1A through 1X, each of R1, R2, R3,
Y2, Y3, and Y6 may be independently a hydrogen atom, a
substituted or unsubstituted C1-C10 alkyl group, a substituted
or unsubstituted C2-C10 alkenyl group, a substituted or
unsubstituted C6-C14 aryl group, or a C2-C14 hetero
aryl group. In this regard, two or more neighboring elements selected
from R1, R2, R3, Y2 and Y3 may be selectively
bonded to each other to form a C6-C12 aromatic ring.

[0068]In Formula 1A through 1X, a is 1 or 2.

[0069]The compound represented by Formula 1 may be any compound selected
from Compounds 1 through 64, but is not limited thereto:

[0070]In certain embodiments, the unsubstituted C1-C30 alkyl
group may be methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl,
iso-amyl, or hexyl. In the unsubstituted C1-C30 alkyl group,
one or more hydrogen atoms may be substituted with a halogen atom, a
hydroxyl group, a nitro group, a cyano group, an amino group, an amidino
group, a hydrazine, a hydrazone, a carboxylic group or salt thereof, a
sulfonic acid group or salt thereof, a phosphoric acid or salt thereof, a
C1-C30 alkyl group, a C1-C30 alkenyl group, a
C1-C30 alkynyl group, a C6-C30 aryl group, a
C7-C20 aryl alkyl group, a C2-C20 hetero aryl group,
or a C3-C30 hetero aryl alkyl group.

[0071]In certain embodiments, the unsubstituted C1-C30 alkylene
group refers to a divalent group having the same structure as the
unsubstituted C1-C30 alkyl group described above.

[0072]In certain embodiments, the unsubstituted C1-C30 alkoxy
group may be represented by --OA where A is an unsubstituted
C1-C30 alkyl group described above. Examples of suitable
unsubstituted C1-C30 alkoxy groups include methoxys, ethoxys,
and isopropyloxys. In the unsubstituted C1-C30 alkoxy group,
one or more hydrogen atoms may be substituted with the substituents which
have been described with the unsubstituted C1-C30 alkyl group.

[0073]In certain embodiments, examples of unsubstituted C1-C30
acyl groups include acetyls, ethylcarbonyls, isopropylcarbonyls,
phenylcarbonyls, naphthylenecarbonyls, diphenylcarbonyls, and
cyclohexylcarbonyls. In the unsubstituted C1-C30 acyl group,
one or more hydrogen atoms may be substituted with the substituents which
have been described with the unsubstituted C1-C30 alkyl group.

[0074]In certain embodiments, the unsubstituted C2-C30 alkenyl
group refers to unsubstituted C1-C30 alkyl groups which have a
C--C double bond in the center or end thereof. Examples of suitable
unsubstituted C2-C30 alkenyl group include ethenyls, propenyls,
and butenyls. In the unsubstituted C2-C30 alkenyl group, one or
more hydrogen atoms may be substituted with the substituents which have
been described with the unsubstituted C1-C30 alkyl group.

[0075]In certain embodiments, the unsubstituted C2-C30 alkynyl
group refers to unsubstituted C1-C30 alkyl groups that have a
C--C triple bond in the center or end thereof. Examples of suitable
unsubstituted C2-C30 alkynyl groups include acetylenes,
propylenes, phenylacetylenes, naphthylacetylenes, isopropylacetylenes,
t-butylacetylenes, and diphenylacetylenes. In the unsubstituted
C2-C30 alkynyl group, one or more hydrogen atoms may be
substituted with the substituents which have been described with the
unsubstituted C1-C30 alkyl group.

[0076]In certain embodiments, the unsubstituted C5-C30 aromatic
ring system refers to a carbocyclic aromatic system having one or more
aromatic rings and 5-30 carbon atoms. When the aromatic ring system
includes 2 or more rings, the 2 or more rings may be fused together or
connected to each other through a single bond. In the unsubstituted
C5-C30 aromatic ring system, one or more hydrogen atoms may be
substituted with the substituents which have been described with the
unsubstituted C1-C30 alkyl group. Specifically, non-limiting
examples of the substituted or unsubstituted C5-C30 aromatic
ring system and non-limiting examples of the substituent of the
substituted or unsubstituted C5-C30 aromatic ring system have
already been described above.

[0077]In certain embodiments, the unsubstituted C2-C30 hetero
aromatic ring system refers to an aromatic system including one or more
aromatic rings that have one or more hetero atoms selected from N, O, P
and S, wherein, in the one or more aromatic rings, the other ring atoms
are carbon atoms (C). In this regard, when the unsubstituted
C2-C30 hetero aromatic ring system includes two or more rings,
the two or more rings may be fused together or connected to each other
through a single bond. In the unsubstituted C2-C30 hetero
aromatic ring system, one or more hydrogen atoms may be substituted with
the substituents which have been described with the unsubstituted
C1-C30 alkyl group. Specifically, unlimited examples of the
substituted or unsubstituted C2-C30 hetero aromatic ring system
and unlimited examples of the substituent thereof have already been
described above.

[0078]In certain embodiments, the unsubstituted C5-C30 aryl
group refers to a monovalent group including a carbocyclic aromatic
system having one or more aromatic rings and 5-30 carbon atoms, and the
unsubstituted C5-C30 arylene group refers to a divalent group
including a carbocyclic aromatic system having one or more aromatic rings
and 5-30 carbon atoms. When the unsubstituted C5-C30 aryl group
and the unsubstituted C5-C30 arylene group include two or more
rings, the two or more rings may be fused together or connected to each
other through a single bond. In each of the unsubstituted
C5-C30 aryl group and the unsubstituted C5-C30
arylene group, one or more hydrogen atoms may be substituted with the
substituents which have been described with the unsubstituted
C1-C30 alkyl group.

[0080]In certain embodiments, the unsubstituted C2-C30 hetero
aryl group refers to a monovalent group including one or more aromatic
rings that has one or more hetero atoms selected from N, O, P and S,
wherein, in the one or more aromatic rings, the other ring atoms are
carbon atoms (C); and the unsubstituted C2-C30 hetero arylene
group refers to a bivalent group including one or more aromatic rings
that has one or more hetero atoms selected from N, O, P and S, wherein,
in the one or more aromatic rings, the other ring atoms are carbon atoms
(C). In this regard, if the unsubstituted C2-C30 hetero aryl
group or the unsubstituted C2-C30 hetero arylene group includes
two or more rings, the two or more rings may be fused together or
connected to each other through a single bond. In each of the
unsubstituted C2-C30 hetero aryl group and the unsubstituted
C2-C30 hetero arylene group, one or more hydrogen atoms may be
substituted with the substituents which have been described with the
unsubstituted C1-C30 alkyl group.

[0082]The compound represented by Formula 1 may be prepared using various
known methods, which would be obvious to one of ordinary skill in the
art.

[0083]For example, the compound represented by Formula 1 can be obtained
by reacting the compound represented by Formula 3 with the compound
represented by Formula 4:

##STR00028##

[0084]In Formulae 3 and 4, Ar, X1 through X6, R1 through
R3, L1, a, m and n have already been defined. In Formula 4, Ha
may be a halogen atom. The compound represented by Formula 1 can be
obtained through a Suzuki reaction between the compound represented by
Formula 3 and the compound represented by Formula 4.

[0085]The light-efficiency-improvement layer 18 including the compound
represented by Formula 1 has a high refractive index, and thus, light
efficiency, specifically external luminescent efficiency, of the OLED 10
is relatively high. For example, the light-efficiency-improvement layer
18 may have a refractive index of 1.8 or more, specifically 1.9 or more,
at a wavelength of about 630 nm.

[0086]In general, an organic light emitting diode includes a plurality of
layers formed of various materials. Accordingly, at least some of the
light generated in an organic layer may be reflected due to total
internal reflection while passing through the layers and thus, may not be
emitted outside the organic light emitting diode. Where the external
luminescent efficiency of the organic light emitting diode is low, even
when the light conversion efficiency in the organic layer is high, the
entire light efficiency of the organic light emitting diode can be
relatively low. However, when light generated in the organic layer 15 is
emitted outside the organic light emitting diode through the second
electrode 17 and the light-efficiency-improvement layer 18, the
light-efficiency-improvement layer 18 may increase the external
luminescent efficiency by constructive interference.

[0087]In FIG. 1, the light-efficiency-improvement layer 18 is disposed on
a surface of the second electrode 17. However, various layers may be
further disposed between the light-efficiency-improvement layer 18 and
the second electrode 17. Meanwhile, although not illustrated in FIG. 1, a
sealing layer for sealing the OLED 10 may be further disposed on the
light-efficiency-improvement layer 18. As described above, the OLED 10
according to the current embodiment may have various modifications.

[0088]FIG. 2 is a schematic view of an OLED 20 according to another
embodiment of the present invention. Referring to FIG. 2, the organic
light emitting diode 20 according to the current embodiment includes a
substrate 21, a light-efficiency-improvement layer 28, a first electrode
23, an organic layer 25, and a second electrode 27 which are sequentially
disposed in this order. The first electrode 23 has a first surface
contacting with the organic layer 25 and a second surface being opposite
to the organic layer 25. The light-efficiency-improvement layer 28 is
formed on the second surface of the first electrode 23. The first
electrode 23 is a transmission-type electrode, and light generated in the
organic layer 25 is emitted outside the organic light emitting diode 20
through the first electrode 23 and the light-efficiency-improvement layer
28. The layers of the organic light emitting diode 20 are the same as the
corresponding layers of the OLED 10, and thus detailed descriptions
thereof will not be provided here. The light-efficiency-improvement layer
28 includes the compound represented by Formula 1 and thus, has a high
refractive index. Accordingly, light generated in the organic layer 25
can be efficiently emitted outside the OLED 20 by constructive
interference. Therefore, the light efficiency of the OLED 20 is
relatively high.

[0089]FIG. 3 is a schematic view of an OLED 30 according to another
embodiment of the present invention. Referring to FIG. 3, the OLED 30
according to the present embodiment includes a substrate 31, a first
light-efficiency-improvement layer 38, a first electrode 33, an organic
layer 35, a second electrode 37, and a second
light-efficiency-improvement layer 39 which are sequentially disposed in
this order. In the OLED 30, the first electrode 31 and the second
electrode 37 are transmission-type electrodes. Accordingly, light
generated in the organic layer 35 can be emitted outside the OLED 30
through the first electrode 31 and the first light-efficiency-improvement
layer 38 and also through the second electrode 37 and the second
light-efficiency-improvement layer 39. The layers of the OLED 30 are the
same as the corresponding layers of the OLED 10, and thus detailed
descriptions thereof will not be provided here. Each of the first
light-efficiency-improvement layer 38 and the second
light-efficiency-improvement layer 39 contain the compound represented by
Formula 1 and thus, have a high refractive index. Accordingly, light
generated in the organic layer 35 can be efficiently emitted outside the
OLED 30 according to constructive interference. Therefore, the light
efficiency of the OLED 30 is relatively high.

[0090]Meanwhile, in an OLED according to an embodiment of the present
invention, an organic layer may be individually patterned corresponding
to R, G and B pixels. Accordingly, the organic layer may include a red
light emitting organic layer, a green light emitting organic layer, and a
blue light emitting organic layer.

[0091]In this regard, a light-efficiency-improvement layer including the
compound represented by Formula 1 described above may be a common layer
with respect to the R, G and B pixels. When the
light-efficiency-improvement layer is a common layer with respect to the
R, G and B pixels, the thickness of the light-efficiency-improvement
layer may be 500 Å to 800 Å. In other embodiments, the thickness
may be 600 Å to 700 Å. If the thickness of the
light-efficiency-improvement layer is within this range, the light
efficiency of the organic light emitting diode may be improved.

[0092]Alternatively, the light-efficiency-improvement layer may include
one or more layers selected from a light-efficiency-improvement layer-R,
a light-efficiency-improvement layer-G, and a
light-efficiency-improvement layer-B. That is, the
light-efficiency-improvement layer can be individually patterned
corresponding to the R, G and B pixels.

[0093]In the current specification, the term "light-efficiency-improvement
layer-R" refers to a light-efficiency-improvement layer formed in an area
corresponding to the R pixel.

[0094]In the current specification, the term "light-efficiency-improvement
layer-G" refers to a light-efficiency-improvement layer formed in an area
corresponding to the G pixel.

[0095]In the current specification, the term "light-efficiency-improvement
layer-B" refers to a light-efficiency-improvement layer formed in an area
corresponding to the B pixel.

[0096]The light-efficiency-improvement layer-R, the
light-efficiency-improvement layer-G and the light-efficiency-improvement
layer-B may be formed on at least one of the second surface of the first
electrode and the second surface of the second electrode.

[0097]The light-efficiency-improvement layer-R, the
light-efficiency-improvement layer-G and the light-efficiency-improvement
layer-B may have the same or different thicknesses.

[0098]The present invention will now be described in further detail with
reference to the following Synthesis Examples and Examples. These
Synthesis Examples and Examples are for illustrative purposes only and
are not intended to limit the scope of the present invention.

SYNTHESIS EXAMPLE 1

Synthesis of Compound 1

[0099]Compound 1 was synthesized according to Reaction Scheme 1:

##STR00029## ##STR00030##

Synthesis of Intermediate 1a

[0100]10 g (44 mmol) of copper bromide and 8 g (35.8 mmol) of
2-aminoanthraqinone were added to 25 ml of a bromic acid and the mixture
was heated at 65° C. until gas was not generated any more. Then
the heated mixture was cooled to room temperature. 1000 ml of 20%
hydrochloric acid solution was added to the reaction product and then
dichloromethane was added thereto to extract an organic layer. The
residual humidity of the organic layer was removed with anhydrous
magnesium sulfate and then dried under a reduced pressure. The resultant
reaction product was refined by column chromatography
(dichloromethane:normalhexane=4:1), thereby obtaining 7.7 g of
Intermediate la (Yield: 75%).

Synthesis of Intermediate 1b

[0101]10 g (34.8 mmol) of Intermediate 1a was added to 100 ml of
tetrahydrofuran (THF) that had been dried in a nitrogen atmosphere and
the temperature was decreased to -78° C., and then, 0.5M (10 mmol)
of 2-naphthylmagnesiumbromide was slowly added thereto. The temperature
was increased to room temperature and the resultant product was stirred
for 3 hours. Then an ammonium chloride solution was added to the reaction
product and then methylenechloride was added thereto to extract an
organic layer. The organic layer was dried over anhydrous magnesium
sulfate to remove the solvent used. The resultant mixture was dissolved
with ethylether, and petroleum ether was added thereto and stirred,
thereby obtaining a solid compound. The solid compound was dried in a
vacuum condition to obtain 17.6 g of dinaphthyidialcohol.

[0102]17.6 g (32.4 mmol) of the dinaphthyldialcohol was dispersed in 200
ml of acetic acid in a nitrogen atmosphere and then, 53.4 g (330 mmol) of
potassium iodide and 58 g (660 mmol) of sodium hypo phosphate hydrate
were added thereto and stirred and refluxed for three hours. The
resultant product was cooled to room temperature to generate a solid
product. The solid product was filtered, washed with a mixture including
water and methanol, and dried in a vacuum condition, thereby obtaining
11.3 g of Intermediate 1b that was light yellow in color.

Synthesis of Intermediate 1c

[0103]5 g (9.81 mmol) of Intermediate 1b was dissolved in 70 ml of THF
that had been dried in a nitrogen atmosphere and then, 4.7 ml (11.8 mmol)
of butyllithium was dropped thereto at -78° C. The resultant
mixture was stirred at -78° C. for one hour and then 2.20 ml (29.4
mmol) of trimethylborate was added thereto. The temperature was increased
to room temperature and left to sit for one hour. Then 2N hydrochloric
acid solution was added to the resultant product and stirred for three
hours to generate a solid compound. The solid compound was filtered and
washed with toluene to obtain 3.27 g (Yield: 70%) of Intermediate 1c that
was light yellow in color.

Synthesis of Intermediate 1d

[0104]3.39 g (35.98 mmol) of 2-aminopyridine and 10 g (35.98 mmol) of
2,4'-dibromoacetophenone were dissolved in 150 ml of ethanol and refluxed
for 12 hours. The reaction product was cooled to room temperature to
generate a white solid and the white solid was washed with a solution
saturated with NaHCO3 to obtain an organic layer. The residual
humidity of the organic layer was removed with anhydrous magnesium
sulfate, and then the resultant organic layer was dried under a reduced
pressure and re-crystallized with dichloromethane and normalhexane to
obtain 8.02 g (Yield: 82%) of Intermediate 1d having a plate crystalline
structure.

Synthesis of Compound 1

[0105]1.85 g (3.90 mmol) of Intermediate 1c and 1 g (3.90 mmol) of
Intermediate 1d were added to a solvent mixture including 2.7 g (19.5
mmol) of potassium carbonate solution and THF, and then 225 mg (0.196
mmol) of Pd(PPh3)4 was added thereto while stirring and the
resultant mixture was refluxed for 6 hours. Then the reaction product was
cooled to generate a solid compound. The solid compound was filtered and
washed with water, ethanol, and THF to obtain 1.73 g (Yield: 71%) of
Compound 1 that was light yellow powder. The resulting compound was
evaluated by NMR analysis with the following results: 1H NMR (400 MHz,
CDCl3) 8.13-8.04 (7H), 8.01 (1H), 7.97-7.92 (4H), 7.86-7.82 (2H),
7.75 (2H), 7.71-7.58 (10H), 7.32 (2H), 7.15 (1H), 6.75 (1H)

[0111]5 g (18.3 mmol) of Intermediate 1d (see Synthesis Example 1) and
4.12 g (18.3 mmol) of N-iodosuccinimide (NIS) were dissolved in an
acetonitrile solvent and stirred at room temperature for 1 hour, and then
100 ml of chloroform was added thereto. Then the reaction product was
washed with 10% sodium hydroxide solution and then washed with a sodium
thiosulfuric acid-saturated solution and water. The resultant product was
dried over anhydrous magnesium sulfate and filtered to remove the solvent
used, thereby obtaining a solid product. The solid product was filtered
and washed with methanol to obtain 5.8 g (Yield: 79%) of an iodine
compound. The iodine compound and 1.76 g (14.5 mmol) of phenyl boronic
acid were added to a solvent mixture including 10 g of potassium
carbonate solution and THF, and then 335 mg of Pd(PPh3)4 was
added thereto while stirring. The resultant mixture was refluxed for 24
hours. Dichloromethane was added to the reaction solution to extract an
organic layer, and the residual humidity of the organic layer was removed
with anhydrous magnesium sulfate and the resultant organic layer was
dried under a reduced pressure. The resultant product was refined by
column chromatography (ethylacetate:normalhexane=2:3) to obtain 2.93 g
(Yield: 58%) of Intermediate 4d.

[0118]Intermediate 1d was prepared in the same manner as in Synthesis
Example 1, and then, 5 g of Intermediate 1d, 4.5 g of
pyrene-1-yl-1-boronic acid, 0.46 g of
tetrakis(triphenylphosphine)paladium, 6 g of potassium carbonate were
dissolved in a solvent mixture including 80 ml of THF and 80 ml of water.
The resultant mixture was stirred at a reflux temperature for 18 hours.
The reaction product was cooled to room temperature and a first organic
layer was separated. 80 ml of dichloromethane was added to an aqueous
layer to extract a second organic layer. The first and second organic
layers were put together and dried with magnesium sulfate to remove the
solvent used, thereby obtaining a crude product. The crude product was
refined by silica-gel-column chromatography to obtain 5.5 g of Compound
12. The resulting compound was evaluated by NMR analysis with the
following results: 1H NMR (DMSO-d6, 400 MHz) δ (ppm) 8.56 (1H, d),
8.51 (1H, s), 8.36 (1H, d), 8.31 (1H, d), 8.28 (1H, d), 8.22˜8.18
(6H, m), 8.10˜8.05 (2H, m), 7.70 (2H, d), 7.61 (1H, d), 7.26 (1H,
t), 6.91 (1H, t)

SYNTHESIS EXAMPLE 8

Synthesis of Compound 14

[0119]Compound 14 was synthesized according to Reaction Scheme 8:

##STR00040##

[0120]Intermediate 4d was prepared in the same manner as in Synthesis
Example 4, and then, 2.9 g of Intermediate 4d, 2.0 g of
pyrene-1-yl-1-boronic acid, 1.03 g of
tetrakis(triphenylphosphine)palladium, and 13 g of potassium carbonate
were dissolved in a solvent mixture including 40 ml of THF and 40 ml of
water. The resultant mixture was stirred at a reflux temperature for 18
hours. The reaction product was cooled to room temperature and a first
organic layer was separated. 40 ml of dichloromethane was added to an
aqueous layer to extract a second organic layer. The first and second
organic layers were put together and were dried with magnesium sulfate to
remove the solvent used, thereby obtaining a crude product. The crude
product was refined by silica-gel-column chromatography to obtain 3.0 g
of Compound 14. The resulting compound was evaluated by NMR analysis with
the following results: 1H NMR (DMSO-d6, 400 MHz) d (ppm) 8.24˜8.13
(4H, m), 8.07 (2H, s), 8.01˜7.97 (4H, m), 7.89 (2H, d), 7.73 (1H,
d), 7.57 (7H, br s), 7.22 (1H, t), 6.74 (1H, t)

SYNTHESIS EXAMPLE 9

Synthesis of Compound 17

[0121]Compound 17 was synthesized according to Reaction Scheme 9:

##STR00041##

[0122]Intermediate 7d was prepared in the same manner as in Synthesis
Example 5, and then 3.94 g of Intermediate 7d, 3.0 g of
pyrene-1-yl-1-boronic acid, 0.7 g of
tetrakis(triphenylphosphine)palladium, and 8 g of potassium carbonate
were dissolved in a solvent mixture including 70 ml of THF and 70 ml of
water. The resultant mixture was stirred at a reflux temperature for 18
hours. The reaction product was cooled to room temperature and a first
organic layer was separated. 70 ml of dichloromethane was added to an
aqueous layer to extract a second organic layer. The first and second
organic layers were put together and were dried with magnesium sulfate to
remove the solvent used, thereby obtaining a crude product. The crude
product was refined by silica-gel-column chromatography to obtain 3.7 g
of Compound 17. The resulting compound was evaluated by NMR analysis with
the following results: 1H NMR (DMSO-d6, 400 MHz) d (ppm) 8.59 (1H, d),
8.56 (1H, s), 8.41 (1H, d), 8.40 (1H, d), 8.34 (1H, d), 8.32 (1H, d),
8.27˜8.19 (6H, m), 8.13˜8.10 (2H, m), 7.91 (1H, d), 7.75 (2H,
d), 7.72˜7.66 (2H, m), 7.31 (1H, d)

SYNTHESIS EXAMPLE 10

Synthesis of 36

[0123]Compound 36 was synthesized according to Reaction Scheme 10:

##STR00042## ##STR00043##

[0124]Intermediates 1a,1b and 1c were synthesized in the same manner as in
Synthesis Example 1.

Synthesis of Intermediate 36d

[0125]3.39 g (35.98 mmol) of 2-aminopyrimidine and 10 g (35.98 mmol) of
2,4'-dibromoacetophenone were dissolved in 150 ml of ethanol and the
mixture was refluxed for 12 hours. The reaction product was cooled to
room temperature to form a white solid. The white solid was filtered and
washed with a NaHCO3-saturated solution. The residual humidity of an
organic layer was removed with anhydrous magnesium sulfate, and dried
under a reduced pressure. Then the resultant organic layer was
re-crystallized with dichloromethane and normalhexane, thereby obtaining
8.02 g (Yield: 82%) of Intermediate 36d having a plate crystalline state.

[0127]Compound 37 was prepared in the same manner as in Synthesis Example
10, except that phenylmagnesiumbromide was used instead of
2-naphthylmagnesiumbromide used to form Intermediate 1b in Synthesis
Example 10. The resulting compound was evaluated by NMR analysis with the
following results: 1H NMR (400 MHz, CDCl3) 8.54 (1H), 8.42 (1H), 8.07
(2H), 7.96 (1H), 7.83 (1H), 7.80 (1H), 7.73-7.48 (15H), 7.35 (2H), 6.87
(1H)

SYNTHESIS EXAMPLE 12

Synthesis of Compound 38

[0128]Compound 38 was prepared in the same manner as in Synthesis Example
10 for preparing Compound 36, except that phenylmagnesiumbromide was used
instead of 2-naphthylmagnesiumbromide used to prepare Intermediate 1b in
Synthesis Example 10 and 2,4'-dibromopropiophenone was used instead of
2,4'-dibromoacetophenone used to prepare Intermediate 36d. The resulting
compound was evaluated by NMR analysis with the following results: 1H NMR
(400 MHz, CDCl3) 8.54 (1H), 8.22 (1H), 7.97 (1H), 7.93 (2H), 7.70 (1H),
7.71-7.52 (15H), 7.35 (2H), 6.92 (1H), 2.73 (3H)

SYNTHESIS EXAMPLE 13

Synthesis of Compound 45

[0129]Compound 45 was synthesized according to Reaction Scheme 11:

##STR00044##

[0130]Intermediate 36d was prepared in the same manner as in Synthesis
Example 10, and then 3.3 g of Intermediate 36d, 3 g of
pyrene-1-yl-1-boronic acid, 0.7 g of
tetrakis(triphenylphosphin)palladium, and 8 g of potassium carbonate were
dissolved in a solvent mixture including 70 ml of THF and 70 ml of water.
The resultant mixture was stirred at a reflux temperature for 18 hours.
The reaction mixture was cooled to room temperature. Then a solid product
in an organic layer was filtered and washed with a solvent mixture
including water and THF, thereby obtaining 2.7 g of Compound 45. The
resulting compound was evaluated by NMR analysis with the following
results: 1H NMR (DMSO-d6, 400 MHz) d (ppm) 9.01 (1H, dd), 8.56 (1H, q),
8.51 (1H, s), 8.39 (1H, d), 8.32 (2H, q), 8.25˜8.19 (6H, m), 8.10
(2H, t), 7.75 (2H, d), 7.09 (1H, dd)

EXAMPLE 1

[0131]Compound 1 prepared according to Synthesis Example 1 was
vacuum-deposited on a substrate to form a light-efficiency-improvement
layer having a thickness of 600 Å. Then an anode was disposed on the
light-efficiency-improvement layer by forming a 15 Ω/cm (1200
Å) ITO. Then, m-MTDATA was vacuum-deposited on the anode to form an
HIL having a thickness of 750 Å and then α-NPD was
vacuum-deposited on the HIL to form an HTL having a thickness of 150
Å. An EML having a thickness of 300 Å was formed on the HTL by
using 97 weight % of DSA constituting a host and 3 weight % of TBPe as a
dopant. Then Alq3 was vacuum-deposited on the EML to form an ETL having a
thickness of 200 Å. Then LiF was vacuum-deposited on the ETL to form
an EIL having a thickness of 80 Å and then Al was vacuum-deposited on
the EIL to form a cathode having a thickness of 3000 Å, thereby
completing the manufacture of an organic light emitting diode.

EXAMPLES 2-9

[0132]Organic light emitting diodes were manufactured in the same manner
as in Example 1, except that Compounds 2, 3, 4, 7, 11, 36, 37 and 38 were
used instead of Compound 1 to form the light-efficiency-improvement
layer.

COMPARATIVE EXAMPLE

[0133]An organic light emitting diode was manufactured in the same manner
as in Example 1, except that Alq3 was used instead of Compound 1 to form
the light-efficiency-improvement layer.

EVALUATION EXAMPLE 1

[0134]Efficiency (cd/A) of each organic light emitting diodes prepared
according to Examples 1 through 9 and Comparative Example was measured
with a PR650 Spectroscan Source Measurement Unit. (produced by
PhotoResearch Co.). The results are shown in Table 1.

[0135]As described in the embodiments of the present invention, an organic
light emitting diode including a light-efficiency-improvement layer
containing the compound represented by Formula 1 has excellent light
efficiency.

[0136]While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will be
understood by those of ordinary skill in the art that various changes in
form and details may be made therein without departing from the spirit
and scope of the present invention as defined by the following claims.